Warm Tips - Please upside down your CO2 tank if you can not refill when the CO2 tank standing. This is because of some tanks have not the dip tube (syphon tube) inside. - pin not included. If needed,please use pin or wrench to Open the vent screw to discharge the residual gas. - NOT compatible with donor tank that has a residual pressure valve. SODA CO2 REFILL ADAPTER - This easy-to-use Cylinder Filling Adaptor will enable you to fill your own CO2 from your larger bulk cylinder into smaller cylinders. - An easy and inexpensive way to fill your own Cylinders at home at a fraction of the cost of getting the refills from your local store. - Can be used with large CO2 tanks with CGA320 connector ( the USA, CAN, Brazil, Colombia) SPECIFICATIONS Material: Brass Size: 2.2x2.2x6cm Packing included: 1 x CO2 Refill Adapter TR21-4 to CGA320 Connector 4 pcs Big Gasket and 4 pcs Small Gasket How it works 1. Cool the Soda-Strean Cylinder in the freezer for 1 hour. 2. Screw the adapter to a commercial CO2 gas cylinder. 3. The empty CO2 cylinder is screwed into the adapter. 4. For most big cylinders: turn the big cylinder upside down. (if you can not refill when the CO2 tank standing, because some of the tank have not the dip tube (syphon tube)inside.) 5. Carefully Open the valve of the large gas bottle(The valve on the Soda-Strean Cylinder closes the flow if it is opened too much. This will happen if you open the big cylinder too much / too fast. The trick is to open the big cylinder very carefully. You will hear the airflow. So to fill it successfully). 6. After about 15-20 sec., The cylinder is completely filled. 7. Close valve of the large gas bottle. 8. Opening the bleed screw to drain residue remaining gas. 9.Unscrew the CO2 cartridge – done.